Divide using synthetic division $$ ( x^{2}-14x-8 ) \div ( x-4 ) $$
Answer
The synthetic division table is:
$$ \begin{array}{c|rrr}4&1&-14&-8\\& & 4& \color{black}{-40} \\ \hline &\color{blue}{1}&\color{blue}{-10}&\color{orangered}{-48} \end{array} $$The solution is:
$$ \frac{ x^{2}-14x-8 }{ x-4 } = \color{blue}{x-10} \color{red}{~-~} \frac{ \color{red}{ 48 } }{ x-4 } $$Explanation
Step 1 : Write down the coefficients of the dividend into division table. Put the zero from $ x -4 = 0 $ ( $ x = \color{blue}{ 4 } $ ) at the left.
$$ \begin{array}{c|rrr}\color{blue}{4}&1&-14&-8\\& & & \\ \hline &&& \end{array} $$Step 1 : Bring down the leading coefficient to the bottom row.
$$ \begin{array}{c|rrr}4&\color{orangered}{ 1 }&-14&-8\\& & & \\ \hline &\color{orangered}{1}&& \end{array} $$Step 2 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 4 } \cdot \color{blue}{ 1 } = \color{blue}{ 4 } $.
$$ \begin{array}{c|rrr}\color{blue}{4}&1&-14&-8\\& & \color{blue}{4} & \\ \hline &\color{blue}{1}&& \end{array} $$Step 3 : Add down last column: $ \color{orangered}{ -14 } + \color{orangered}{ 4 } = \color{orangered}{ -10 } $
$$ \begin{array}{c|rrr}4&1&\color{orangered}{ -14 }&-8\\& & \color{orangered}{4} & \\ \hline &1&\color{orangered}{-10}& \end{array} $$Step 4 : Multiply by the number on the left, and carry the result into the next column: $ \color{blue}{ 4 } \cdot \color{blue}{ \left( -10 \right) } = \color{blue}{ -40 } $.
$$ \begin{array}{c|rrr}\color{blue}{4}&1&-14&-8\\& & 4& \color{blue}{-40} \\ \hline &1&\color{blue}{-10}& \end{array} $$Step 5 : Add down last column: $ \color{orangered}{ -8 } + \color{orangered}{ \left( -40 \right) } = \color{orangered}{ -48 } $
$$ \begin{array}{c|rrr}4&1&-14&\color{orangered}{ -8 }\\& & 4& \color{orangered}{-40} \\ \hline &\color{blue}{1}&\color{blue}{-10}&\color{orangered}{-48} \end{array} $$Bottom line represents the quotient $ \color{blue}{ x-10 } $ with a remainder of $ \color{red}{ -48 } $.